DNA and Criminal Justice


On August 2, 1986, the body of 15-year-old Dawn Ashworth was found in the woods of  Leicestershire, England, raped and strangled.  The specific modus operandi recalled the murder of Lynda Mann in the same vicinity three years earlier. Mann’s case had never been solved.

The prime suspect in the case was a local 17-year-old boy with learning disabilities who admitted to Ashworth’s murder under police grilling.

But wait, there’s DNA evidence
A year earlier, genetics researcher Alec Jeffreys at the University of Leicester had developed a method of extracting and comparing DNA from bodily fluids. He compared semen and blood samples that exonerated the youth. “I have no doubt whatsoever that he would have been found guilty had it not been for DNA evidence,” he said later.

With a serial killer on the loose, local police mounted a massive effort to find him. Evidence led them to local baker Colin Pitchfork. His DNA placed him among the relatively small number of men who could have been responsible for the crime. With a preponderance of evidence against him, he pled guilty to his crimes and was sentenced to a long prison term.

And thus, in one case, was the first person ever absolved and the first person ever convicted based on DNA evidence. Thousands have since been cleared or implicated using the technology. It has even been used retrospectively by The Innocence Project to free 350 Americans wrongly convicted of serious crimes, 20 of them on death row.

Advances in Forensic DNA
DNA is the basic operating system for life, determining all of our common and unique characteristics. Humans share 99.5% of DNA with each other (and 98% with chimps.)

Today, DNA extraction and comparison technology are vastly faster and more precise than in 1986. Recent developments have allowed labs to produce a usable DNA profile in 90 minutes, as compared to 90 days in the early days of DNA testing. In addition, federal, state and local law enforcement maintain a database of DNA profiles, knowns as CODIS, against which to compare forensic samples. Lawmakers have been challenged to find the right balance between individual and societal interests in determining whose DNA should be stored.

Law enforcement professionals use DNA samples regularly in their work and need to be experts in their collection and use in building a criminal case.

Graduate Studies for Law Enforcement Professionals
Anderson University offers a master’s degree program at the Lowcountry Graduate Center designed to provide law enforcement professionals with the tools and training they need to advance their careers to middle and senior management positions.

Offered as a hybrid– with some courses online and others in classrooms – the 36-credit, 20-month graduate program includes the course Applied Research Methods, which covers the use of DNA profiling. To accommodate professionals working full-time in law enforcement, classes are scheduled monthly for two full days back to back. Click here for more information about the Master’s Degree program.

April 25 has been designated each year as International DNA Day to commemorate the date in 1953 that James Watson, James Crick, and colleagues published their discovery of the DNA’s structure. But it’s celebrated every day someone is caught or cleared of a crime by DNA evidence.